eChapters

I. FILL UPS

1. _____ works on the principle based on gravitational force
2. Gamet divider is otherwise known as_____.
3. Gamet divider works on the principle based on_____.
4. _____ method is suitable for seeds requiring working samples upto 10grams and seeds not chaffy and do not bounce and roll.

Cultivated plants in general including the spice crops observed today have been evolved through selections from their weedy and wild types. Apart from this, there had been another force which could bring the wild forms into cultivated forms named human intervention which is actually the process of domestication. Natural mutations and genetic recombination after selfing and crossing also played a significant role in the entire process. Whereas, natural forces take a long time to come into act, the techniques of plant breeding was devised and fine tuned throughout passing of times, essentially to accelerate the speed of evolution using these natural phenomenons. It was, therefore, mandatory for us to know the modes of reproduction and pollination to create variability in natural population and make all thise happen to what we see today in organised cultivated forms. Moreover, knowledge on reproduction of different plant species helps the breeder to choose the right breeding procedure to be used for crop improvement. Modes of reproduction help to evaluate the genetic constitution of crop plants by determining the extent of homozygosity or heterozygosity which, in turn, are unanimously applicable to any plant. To comprehend modes of reproduction in spice crops effectively, understanding about the floral biology is absolutely necessary. Plant reproduction, a process by which one species gives birth to its offsprings, may be of two types

Molecular markers may be a short DNA sequence that flanks base pairs like SNP, a Single Nucleotude Polymorphism, small fragment or SSR Single Sequence Repeat or an extended site as in the case of microsatellites. Schematic representation of the SSR assay is shown in Fig. 1. Genetic markers have to be easily identified, linked to a specific locus and polymorphic. Molecular markers are subdivided into codominant monolocus and polyallelic markers and the second group contains dominant, polyallelic and biallelic markers. 

Abstract

People dealing with forest tree seeds are very much concern with the collection and supply of pure and quality seed. Assessing genetic purity of tree seed is always a challenge. Besides, studying tree diversity and tree improvement are also the key components of forestry. With the discovery of DNA based molecular markers these tasks have been made easier and authentic. So, the basic concepts behind different molecular markers were the principal concerns of this chapter. It has been focused here about the pros and cons of the markers along with their applicability. The application may be expanded towards hybrid seed testing and even to clonal forestry.

Vegetables have always been looked upon as an essential part of diet and are necessary for human health and well-being. Vegetables supply many kinds of nutrients, e.g., carbohydrates, proteins, minerals, vitamins, fibers, phytochemicals, etc. and also add flavour, colour and crispness to foodstuffs. For developing modern day vegetables, breeders have utilized an understanding of genetic principles and applied them for the improvement of these crops. They often make crosses (hybridization) between a crop plant and a related or wild species (a wide cross) enabling valuable genes to be used for genetic improvement of the crops. Over the last few decades, molecular breeding is supplementing plant breeder’s efforts for accelerated genetic enhancement bringing about a revolution in this area. This approach demands efficient procedures for the routine introduction of foreign DNA into plant genomes and utilizing them for the production of novel types of vegetable. In this chapter, attempts have been made to review most of the available molecular breeding techniques, which can routinely be employed in various aspects of vegetable improvement.

Cultivars are developed by selecting for desired traits or by removing undesirable traits that are controlled by genes (the blueprint for all characteristics in living organisms) from existing varieties or breeding lines. The plant species, varieties and clones are identified or selected by their physical features since olden times. However, these traits would change with respect to environmental and climatic conditions. The biochemical parameters like enzymes, proteins, alkaloids, etc. are also likely to change due to the stages of development of plant tissue. Successful selection strategies are dependent on the breeder’s ability to distinguish genetic effects from environmental effects on a visible or measurable trait. Therefore, the scientists resorted to use ‘genetic marker’, i.e., any stable and inheritable variation that can be measured or detected by a suitable method and can be used subsequently to detect the presence of a specific genotype or phenotype, which otherwise is very difficult to detect. Presently, the breeders and scientists all over the world are pursuing mostly DNA or molecular markers.

Botany

The plant is highly cross pollinated due to heteromorphism and bees being the major pollinators.

Varieties: PKM 1 & PKM 2

Method of seed production : Seed to Seed.

Land requirement : Uproot all the wild and non specific moringa trees if any near the field within a radius of 1500ft. Good drainage facility is must for moringa.

Isolation requirement : A distance of at least 500 M is necessary for seed production.

Season : Early season (July August), Mid season (September), Late season (October -November). Best season is September October, so that flowering starts during summer which facilities better pollination and seed set.

A. General Morphology

2.1 The Root

It is the organ of a plant that typically lies below the surface of the soil.The root is best defined as the non-leaf, non-nodes bearing parts of the plant’s body. However, important internal structural differences between stems and roots exist. Root spices are, rather surprisingly, rare. Some popular examples of spices having roots are: Apium graveolens (Celery), Armoracia rusticana (Horse radish), Coriandrum sativum (Coriander), Ferula asafoetida (Asafetida), Glycyrrhiza glabra (Licorice), Levisticum officinale (Lovage), (Petroselinum crispum (Parsley), etc. All of the mentioned plants have aromatic roots.Roots of gingiberaceae are adventitious and storage roots arise from among the nodes of these scales.

Mulching is a practice of covering the surface of soil with plastics, organic and non-organic materials like straw, grasses, sands, stones (boulders), synthetic plastics, etc. to reduce evaporation and to moderate wide fluctuations in diurnal soil temperature, especially in the root zone environment. It controls external evaporability and reduces energy supply to the evaporating site by cutting off solar radiation falling on the ground. Its main function is limited to control first stage of drying, which helps in improving moisture status and reducing soil temperature (Loy and Wells, 1975), besides checking seedling mortality and improving crop stand. It also suppresses weed-flora and reduces weed competition with crop for water and nutrients making them available in greater quantities for crop plants. Moreover, mulching helps in increasing downward movement of water, and its storage deep in the profiles escapes evaporation due to reduction in thermal gradients and exchange of vapours. The effectiveness of mulches in conserving moisture has generally been found to be higher under more frequency of rainfall, drought conditions and also during early period of plant growth when canopy cover remains scanty.

Vegetables are cheaper source of carbohydrates, proteins, minerals, vitamins and dietary fibers, and hence, assume a place of very great importance in the diet of individuals. All kinds of vegetable are grown almost universally. India occupies the prime position in the production of vegetable crops and is the second largest producer of vegetables in the world. The area and production of vegetables in India have been increasing during the post-green revolution period, and the country is heading towards another revolution in the form of Golden Revolution. However, there is an utmost requirement for genetic improvement of vegetable crops in terms of productivity, qualitative characters and resistance to biotic and abiotic stresses. For any genetic improvement programme, the presence of genetic variation is pre-requisite and mutation is the ultimate source of this heritable variation.

Mutation technique that holds promise of generating a much wider desirable variability than classical breeding has been refined. Out of 2275 mutant varieties worldwide in all crops, as many as 66 mutants are in vegetables. In terms of percentage, China, India, USSR, The Netherlands, The United States of America and Japan account for 26.8, 11.5, 9.3, 7.8, 5.7 and 5.3%, respectively of mutagen varieties in all crops. Such varieties are 3% in case of vegetables. After mutation treatment by a mutagen to a specific plant, DNA alterations (deletion, duplication, inversion, translocation, or transposition of larger DNA fragments, or simple basic pair changes) occur and lead to the DNA sequence change. Hence, new characteristics of that plant are established. In fact, induced mutations supply us with many new plant lines, which may be used as primary materials for crop breeding. Hence, mutation breeding seems to be an effective and ultimate option to improve vegetable crops in the shortest possible time. A large number of new promising varieties in different crops, including vegetables, have successfully been developed worldwide using various mutagens (Chopra, 2005).

Aims and Objectives

It has become evident that in order to achieve the food production targets of the future, a major effort will be required to enhance the seed replacement rates of various crops. This would require a major increase in the production of quality seeds, in which the private sector is expected to play a major role. At the same time, private and Public Sector Seed Organisations at both Central and State levels, will be expected to adopt economic pricing policies which would seek to realise the true cost of production. The creation of a facilitative climate for growth of a competitive and localised seed industry, encouragement of import of useful germplasm, and boosting of exports are core elements of the agricultural strategy of the new millennium.

Biotechnology will be a key factor in agricultural development in the coming decades. Genetic engineering/modification techniques hold enormous promise in developing crop varieties with a higher level of tolerance to biotic and abiotic stresses. A conducive atmosphere for application of frontier sciences in varietal development and for enhanced investments in research and development is a pressing requirement. At the same time, concerns relating to possible harm to human and animal health and bio-safety, as well as interests of farmers, must be addressed.

Globalization and economic liberalization have opened up new opportunities as well as challenges. The main objectives of the National Seeds Policy, therefore, are the provision of an appropriate climate for the seed industry to utilize available and prospective opportunities, safeguarding of the interests of Indian farmers and the conservation of agro-biodiversity. While unnecessary regulation needs to be dismantled, it must be ensured that gullible farmers are not exploited by unscrupulous elements. A regulatory system of a new genre is, therefore, needed, which will encompass quality assurance mechanisms coupled with facilitation of a vibrant and responsible seed industry.

Introduction

Agricultural soils harbour a rich variety of nematode fauna, where they coexist with a myriad of other microorganisms. It has been estimated that one cubic meter soil of highly fertile field may contain as many as 3×10¹⁴ bacterial cells (300 g), 5×10⁸ protozoa (39 g), 1×10⁷ nematodes (12 g) and fungi (400 g), besides other organisms. The nemic fauna comprises of free-living (saprophagous and microbivorous), predatory forms and plant parasites (phytophagous). In addition, certain animal and insect parasitic forms may spend a part of their life cycle in soil. Plant parasitic nematodes (PPNs) exist in poly-specific communities and attack all types of plants- cultivated or wild. They possess a needle-like stylet or spear at their anterior end, which is used to puncture the plant cells and ingest the cell contents. Majority of PPNs dwell in soil and draw their nutrition from plant roots. Only a few forms attack the above ground plant parts such as stem, leaves, inflorescence and seeds. PPNs may be ectoparasites (feed from outside and do not enter plant tissues) or endoparasites (enter inside the plant tissues). The endoparasites spend a part of their life cycle in soil or may come out into the soil to re-infect the other roots. These may be further categorized into migratory or sedentary types. The migratory forms keep on moving, feeding and laying eggs that are scattered in soil or plant tissues. The sedentary nematodes are more harmful and a particular stage of their life cycle infects the plant and establishes a feeding site by modifying plant tissues by their enzymatic secretions. The females of sedentary nematodes usually attain swollen shapes upon maturity and lay hundreds of eggs in clusters.

Plant parasitic nematodes are ubiquitous, and so far, more than 1800 species have been recorded. They are obligate parasites and must feed upon plant hosts, thus, debilitating the plants to some extent. The extent of direct damage by the nematodes to plants depends on several factors viz., nematode density in soil, nature of parasitism (ectoparasite or endoparasite), host susceptibility, cropping pattern, edaphic factors (mainly soil texture and moisture) and ambient climatic conditions (like temperature and relative humidity). Nematodes, by themselves, rarely kill the plants to ensure their own survival. Nematodes also inflict considerable indirect damage to crops by interacting with other plant pathogens (fungi, bacteria and viruses) to cause disease complexes in which nematodes act as incitants, aggravators, or vectors.

7.1 Plant Tissue Culture

Spices have great socio-economic impact in moden food habit of human but loss of resources day by day due to various reasons (industrialization, high population pressure) make the access of these valuable spices limited to people. Low production is general phenomena of common spices due to lack of high yielding varieties. Hence there is a need to improve the propagation method to meet the gap between demand and supply. Conventional vegatative propagation method is common approach for propagation but low multiplication rate, seasonal dependency and susceptible to abiotic stresses and diseases are major problems to achieve the optimum productivity. To overcome these drawbacks scientists have chosen the plant tissue culture technique (a modern approach of biotechnology which deals with the propagation the valuable/endangered plants under laboratory condition). Details about this technique and its role on spices are given below.

Plant Tissue Culture: Basic Components and Objectives

The technique of growing of a whole plant cell, tissue or organ under an aseptic condition in suitable synthetic medium is termed as plant tissue culture (Thorpe, 2007). De-differentiation and re-differentiation are two essential fundamental processes which help in the physio-morphological development of the plant.

Notified Varieties of Different Seed Spices

Leaves are alternate in distichous arrangement; lamina long and linear and leaf sheath covering the internodes; ligule membranous and auricle claw shaped. The inflorescence is a spike and florets are borne on rachis node. Each spikelet has three florets. In two row barely, lateral spikelets become sterile.

Agathi is a fast growing tree upto 10m. tall. Branching is drooping. The stem bark is deeply furrowing forming cork like plates. Leaves are compound, pinnae, 20 to 30 cm. long glabresence to pubescent. Leaflet oblong rounded 18 to 24 pairs of leaflets that are green to dark green mostly, bitter free. Inflorescence is a raceme 4 to 7 cm long and bearing 2 to 5 flowers that are white, red, yellowish and pink. Flowers are 5 to 10 cm long, 3cm wide, curved calyx bell shaped 2 cm long, 2 lobed, fine teeth like serration, fleshy. 

Crop improvement is a continuous process. Crop improvement aims to genetically enhance, enrich and empower the crop plants with superior performance, enhanced yield level, higher quality of food, nutritional, fodder, energy produce and adaptability to climate change and crop growing environments. The intrinsic virtues of the improved cultivars could be sustained mainly through the production of the quality assured seeds endowed with genetic capabilities. The quality assured seed delivery system is through the seed chain from the basic seeds through Nucleus-Breeder-Foundation-Certified seed. Quality seed production system need to be based on genetic, breeding and seed technological protocols including field and laboratory testing to ensure very high genetic purity, true to type and superiority.

Successful onion cultivation begins with vigorous, disease-free seedlings and their timely establishment in the field. Seed quality, nursery-bed preparation, growing medium, nutrition, irrigation, weed control and protection against pests and diseases determine seedling performance. This chapter explains conventional and modern nursery-management practices, including raised beds, plug trays, protected structures, soilless media, fertigation and climate-controlled production. It also discusses seedling selection, hardening, transplanting age, spacing and field establishment. Mechanized, robotic and precision transplanting systems are examined as solutions to labour shortages and uneven planting. Climate-resilient nurseries, sensors and automation can further improve transplant survival, resource efficiency, uniformity, productivity and sustainability.

Nursery management is indeed a very important operation in successful growing of vegetables especially those, which are raised through seedlings in properly managed nursery beds. Raising nursery from seed provides an easy and convenient way to nourish tender young seedlings in a well-managed small and compact area. The nursery area can be conveniently protected from natural hazards, seed borne diseases and insect-pests and can be well managed economically. Some of the vegetable seeds are very costly, for which it is necessary to raise nursery in the most-optimum conditions. In areas where land holdings are small (in hills), nursery raising helps in making economical use of land for about one month and provides enough time to mature for previous crop, harvesting, threshing and land preparation for next crop. Most of the vegetable crops like cabbage, cauliflower, tomato, eggplant, sweet pepper, hot pepper, onion, celery, parsley, lettuce, etc. can successfully be raised through seed by growing them in the nursery and then transplanting in the field.

“A vegetable nursery is a place or an establishment for raising or handling young vegetable seedlings until they are ready for more permanent planting.”

Nursery can be maintained either for personal or commercial purpose, and each has its own advantages and disadvantages. Seedlings raised for own planting will be true to type, sound and healthy. On the other hand, seedlings purchased from outside may not be true to type, vigorous and healthy and may not arrive at destination in due course of time.

1. SELECTION OF SITE

Select a location where one could ensure semi-shady conditions. Well drained medium-loam soil; rich in organic matter and neutral soil pH. An irrigation source in the vicinity with natural pH water is highly desirable.

I. FILL UPS

1. _____ number of beds measuring 8 m, 0.6 m are sufficient for raising sufficient seedling for one hectare.
2. Seeds are sown singly at _____distance apart in the furrow.